Real Bad Tape Mastering: How Some Components Make It Worse

[sanlyn]

BAD TAPE CHRONICLES (Cont'd):

How does pass-thru or line tbc handle these encoding problems? In some cases, not so well.

The Source: Retail VHS tape transfer from digital encoding of a French film, "The Music Teacher", English subtitles. It might be a favorite out-of-print movie with music lovers, but it's a visual mess otherwise. Original film is 1.85:1 wide screen, but the VHS is 4:3 with image sides chopped off. This looks like a poorly encoded, bitrate starved original with artifacts --motion smearing and ghosting from typical aggressive dnr. Color is by Agfa film, which is pretty horrible and shifts color balance with every camera shot.

In the scenes below the music teacher slowly paces around his young singing student to test her concentration. Motion smear and ghosting in the sloppy digital master from which the tape was made are obvious, but with some components it looks worse.

Start with a plain unfiltered version of a captured scene with no line tbc. A working AVT-8710 is used on all samples due to Macrovision effects. All captures were into VirtualDub/Lagarith. All are mp4.

A1: PV-S4670 SVHS VCR >> no line tbc >> AVT-8710 >> AIW 9600XT

A2: PV-S4670 SVHS VCR >> RD-XS34 pass-thru >> AVT-8710 >> AIW 9600XT

A3: PV-S4670 SVHS VCR >> DMR-ES10 pass-thru >> AVT-8710 >> AIW 9600XT

A4: PV-S4670 SVHS VCR, DMR-ES15 pass-thru, AVT-8710, AIW 9600XT

A5: Panasonic AG-1980 >> AVT-8710 >> AIW 9600XT
6 pixels of information are missing from the bottom border: one reason I don't like this VCR.


A6_cleanup: PVS4670_ES15_AVT8710_9600XT.mp4
A6: (final edit). I chose the ES15 version. But it took some heavy filtering to get there.

The RD-XS34 used as pass-thru displayed the least damage and not much tendency to posterize. But unfortunately its 2003-era caps and other aging circuitry are adding 24 pixels or more of foggy output across the top border, often losing almost all detail in some scenes. The fog is highly noticeable on TV and in projection, which is how the movie will be viewed. Sad to say, I can no longer use the RD-XS34 for pass-thru or for recording VHS.

[sanlyn]

BAD TAPE CHRONICLES (Cont'd)

The attached "chase scene" video sample is the short scene from which the comparison frames are taken. It's from an early capture of the same tape discussed above. It's been inverse telecined. Capped with old AG-1980 and AIW 7500 AGP to lossless huffyuv.

In the movie a small crowd is chasing a street thief into the woods, followed by the main character in a horse-drawn carriage and who eventually rescues the thief. Early in the clip there are high-speed closeups of the thief's face. Distortion is easily seen in the sloppy encoding.

video:Inverse_telecined_capture_chase_scene.mp4

The sample frames show how each line tbc device and component handles the badly encoded closeups:




B1: TMT4z >> PV-S4670_no Line TBC >> AVT8710 >> 9600XT.jpg




B2: TMT1h >> PV-S4670 >> RDXS34 Pass-thru >> AVT8710 >> 9600XT.jpg




B3: TMT2k >> PV-S4670 >> ES10 pass-thru >> AVT8710 >> 9600XT.jpg




B4: TMT3m >> PV-S4670 >> ES15 pass-thru >> AVT8710 >> 9600XT.jpg




B5: TMT3n >> AG-1980 >> AVT8710 >> 9600XT.jpg




B6: oldTMT >> AG-1980 >> AVT8710 >> AIW 7500.jpg
Made with another AG-1980 three years ago, same tape.